William keuffel



(No Model.)

. W. KEUFFEL.

SURVEYORS TARGET.

No. 337,959. Patented Mar, 16, 1886.

N. PETERS. Phnloblhogmphu. Washington, D. C.

Unrrn fira rns XVILLIAM KEUFFEL, OF HOBOKEN, NE\V JERSEY.

SU RVEYORS TARGET.

forming part of Letters Patent No. 337,959, dated March 16,1886.

Application filed November 18, [855.

To all whom, it may c0nccrn:

Be it known that l, \VILLIAM KEUFFEL, of Hoboken, Hudson county, in the State of New Jersey, have invented a certain new and useful Improvement in Surveyors Targets, of which the following is a specification.

I employ rollers through which the springs press on the staff. Each turns on a fixed pin in its interior. This allows the friction to be gentle and uniform without danger of abrading the staff. A pinching-screw acts on the staff through the medium simply of a shoe, to confine the target when it is set. The rollers are preferably of hard rubber. They should be of such material as to each produce a uniform friction on its pin to resist a change of position of the target.

The accompanying drawings form a part of this specification, and represent what I consider the best means of carrying out the invention.

Figure 1 is a front view; Fig. 2. a vertical section; Fig. 3, a rear view, and Fig. 4 a plan View. The remaining figures show a modification. Fig. 5 is a plan View; Fig. 6, a Vertical section of a portion; and Fig. 7 shows the single spring detached.

Similar letters of reference indicate corresponding parts in all the figures where they occur.

A is the staff-a straight rod of wood ofrectangular section-carrying graduations a on the front face.

B is the body of the target, and b the ordinary beveled edge of the opening therein. The latter is graduated to serve vernierwise. There are the usual crosslincs, b, on the face of the target.

G is a rigid frame or strap secured to the back of the target by screws 0.

D is a pinching-screw tapped through a boss in the strap 0, and provided with a large milled or fiat head, D. Its point carries a concave shoe, E. When the target is in the desired position, the screw D is operated to force the shoe E into firm contact with the staff A and hold the target firmly.

F F are springs riveted on the inner faces of the strap 0 on opposite sides, as shown. Each end of each spring is bent around to form an eye, F, which tightly embraces a pin, G.

Serial No. 1832M. (No model.)

Each pin G is embraced by two springs, leav ing a considerable space between. On this space is fitted a short length of hard-rubber tubing, H, which turns with uniform friction on its pin Gas it rolls on the staff A under the pressure of the springs F when the target is moved up and down. These rollers H H embrace the stalf A between them. Similar springs similarly equipped with a cross-pin at each end, carrying a corresponding roller, compress the staff between themselves and Corresponding rollers similarly mounted on pins firmly fixed in eyes A on the back of the target.

The springs should be adjusted to press with considerable force against the respective faces of the staff. The rollers preserve the surfaces of the staff from being abraded. They transmit the pressure of the springs under conditions which give a uniform frictional resistance to the movement of the target up and down. The target may be shifted up and down to any required extent by the direct application of the hand, or by any other convenient force. The rollers should create a friction a little more than sufficient to resist gravity, and hold the target in place with gentle "force. Vhenever it is desired to hold the target more firmly, the screw D is operated to press with any desired degree of force against the back face of the staff A. The force is transmitted through the shoe E. No abrasion is produced.

Modifications may be made in the forms and proportions without departing from the priir ciple or sacrificing the advantages of the in vention. Parts may bensed without the whole. I can dispense with the eyes A and the corresponding pins and rollers, allowing the back face of the target to slide directly 011 the front face of the staff, and having only the other faces of the staff acted on by the springs through the medium of rollers.

Figs. 5, G, and 7 show a modification in which only one spring is employed. There is a roller in each end of the spring mounted on a pin carried in the spring, so that the friction between the roller and the pin is subject to the force of the spring and is constant, as in the other and preferable arrangement. In this modification one face of the staff is IOC pressed against by the roller, while the opposite face bears against a rigid arm extending out from the target. This arm and also the arm or frame which carries the spring and pinching-screw are each provided with a hook,

which engages in a gain in the back face of the strait. These hold the parts together strongly, but loosely. lhe gentle firmness required to hold the target in place on the rod and allow it to be shifted is due to the arm and the springactuated roller. The pinching-screw in this modification, as in the other arrangement, acts through a shoe, and by its aid presses on the staff without affecting the force of the 5 spring. I prefer the whole as shown.

I claim as my invention 1. The surveyors target descr bed, having WVILLIAM KEUFFEL.

\Vitnesses:

CHARLES R. SEARLE, LYNDON P. SMITH. 

